Door latch construction



Jan. 8, 1952 0. J. SEAMAN ErAL DOOR LATCH CONSTRUCTION Filed Oct.

FIE. m I Snow M5 DAV/13 JEEAMAN &

ALBERT E. W0 00 Patented Jan. 8, 1952 Y DOOR LATCH CONSTRUCTION David Joseph Seaman and Albert Edward Wood,

Battle Creek, Mich. Seaman said Wood assignor to said Application October 2, 1947, Serial No. 777,528

This invention relates to door latch constructions and to the strike plates employed in conjunction therewith.

It is an object of the invention to provide an improved and simple door latch construction, the latch member of which is capable of being automatically actuated to permit opening and closing movements of the door by the manual force or energy normally employed to effect such movements but which latch member, in the closed condition of the door, is capable of bein held in a substantially locked condition with respect to the strike plate so as to resist opening of the door at least by the force or energy normally applied or exerted for such purpose and this without the necessity of employing any separate key action.

It is also an object of the invention to provide a door latch construction, the latch member of which is capable of being held in a substantially locked condition with respect to the door jamb strike plate simply by turning an actuating member (which may be in the form of a hand lever or rotary knob) the position of which is readily discernible so as to indicate to a person wishing to open the door that the latch member is either freed for a normal opening movement of the door or is held substantially locked. In other words, the position of this actuating member serves as a signal to indicate the particular condition of the door latch. Primarily, the latch mechanism pro vided in accordance with the invention is intended for use on bathroom, bedroom lavatory, fitting room, and doors generally as employed for rooms in which privacy is required at given moments yet not to the extent as normally required and employment of any key action and which latch mechanism permits of the door being opened and closed by a simple push or pull action.

In the accompanying drawing,

Fig. I is a plan view partly in section illustrating one embodiment of the invention with the door shown in the locked, or substantially locked, condition,

Fig. II is a sectional elevation of Fig. I, and Fig. III is a similar view to Fig. II, but showing the door latch in the condition in which it can 3 Claims. (Cl. 29274) be readily displaced upon the normal force being applied to open or close the door.

In carrying the invention into effect in one convenient manner, as illustrated in the drawings, a door latch construction is provided consisting of a, cylindrical body part i, having a plunger 2, the stem portion of which is axially slidable through the central opening 3 of a collar 4 secured by screw threadin 5 in one end of the body part I, and the opposite end of which plunger is formed to provide a disc 6 which forms a bearing surface for a pair of coaxial coil springs l and 8, the opposite ends of which are capable of having bearin engagement with a collar 9, adjustable axially along a screw threaded shank l0, normally secured in a set position upon such shank. The latter, at its outer end corresponding to the outer longitudinal edge of the door, remote from the door hinges, is formed with a disc part II incorporating on its outer surface a central hemispherical, or substantially hemispherical, latch member l2, whereby the latter is axially slidable within the hollow body part I with or against the action of the springs 1 and 8. The latch member l2 extends slidably through a central opening [3 in a flange plate M at the forward end of the hollow body part I, which flange plate is preferably of circular shape and secured upon the door by means of the securing screws l5.

The springs 1 and 8 are of different strengths, the inner spring 1 being a relatively light spring and serving permanently to urge the ball-ended latch I2 outwardly, with respect to the flange plate l4, but offering no appreciable resistance to an inward sliding movement of the latch part 12, such as would be produced by the manual force normally applied to open or close the door for engagement or disengagement of the latch part l2 with the strike plate H3 secured upon the door jamb 11. This relatively light spring I therefore is permanently in operation and provides for the obtaining automatically of free latching op erations.

The spring 8 on the other hand is normally ineffective, and is a relatively strong or stiff spring, which is capable, however, of being brought into effective operation consequent upon the angular setting of a cam l8, secured, as by a grub screw l9, upon a shaft 20, which is secured transversely of the door in a plane perpendicular to the longitudinal'axis oi the hollow body part I, and carries on opposite sides of the door a pair of handles 2| and 22.

The cam I8 is secured upon the shaft 20 so as to lie opposite the outer end of the stem 2a of the plunger 2, whereby the latter is maintained, by the force of the light coil spring 1, in contact with the actual cam surface Illa, the latter having a high part I81) at one end and a low part 180 at the opposite end. The arrangement, is such that with the handle 2| in the vertical position as shown in Figure II the high cam part 18b exerts inward pressure against the: stem 2a such that the disc 6 thereon is displaced axially and after being brought up against the corresponding end of the stiff coil spring 8 compresses the latter and thereby brings this spring. into effective operation to impose a load upon the latch member l2 which is additional to that exerted by the light spring 1 and may (by suitable adjustment or design) be sufiicient as to hold the latch member fast against inward displacement or at least prevent the same from being forced back against the combined spring action by the manual force normally available to pull the door open.

Obviously other angular positionsof thehandle H are possible. For instance provision may be made whereby this handle is horizontal when the stiff spring 8- is effective. Normally, of course, the, handle will be positioned so that thelow part of the cam isagainst the stem 2a. and the stiff spring 8 is accordingly outof action. This provides for free opening and. closing door movements with automatic latching of the member l2 with the strike plate 23. If new it is desired to lock the door in the. closed position against the ,manual force normally available to pull the door open, this can be readily effectedby turning the handle 21- to cause the high part we of the cam to be brought up against the stem 2a The resulting cam action causes the stemv to be forced inwards so that it makes contact with the corresponding endof the sti-if. spring ii and by the continued inward movement of the stem causes the stiff spring to be compressed between the head 6 and the collar 9, whereby both springs are then efiective to apply a loading force to the latch member l2, the eiTect of which is to resist considerably inward movement. of this member. or substantially to lock the same in its projected position.

Persons accustomed. to using a door with a door latch. construction as described. herein will learn to appreciate that when the handle 2i is in one position, as for examplethe vertical posi- .tion. as. shown in Figure. II, or in. a horizontal position if the locked condition of the latch. is arranged to be eiiected with the handle 2| horizontal, that this means thatthe door is intended to be locked against opening The collar 9 as above stated is fast upon the shank ill although adjustable therealong and the permitted axial reciprocation of the latch member l2 and its associated parts is provided for by the pin E l engaging the elongated slot- 25 in the barrel l.

The construction alsoprovides for the effecting of an initial setting of the ball end of the latch member lz'whereby thersame may be caused norreally to engage with a greater or lesser degree of friction. This adjustment may be effected simply by rotating the projecting ball end of the latch member i2 to-cause the threaded stem it thereoi to be screwed backwards or forwards with respect to the collar 2 and thereby increase or decrease the normal loading of the light spring A pinhole 26 in the said ball end serves for the introduction of a pin to facilitate such rotational adjustment. Adjustment islalso possible by means ofthe collar 4,

which can be turned to relieve or increase the initial pressure of the disc 8 on the light spring 1 and thereby provide for the obtaining of the desired free latching action of the latch member l2.

The strike plate 23, as above stated, is secured to the door jamb which latter may also be fitted with a door stop 27 corresponding to the fully closed position of the door and preferably the strike plate, which is formed with a depression 28 providing forcammed engagement and disengagement of the ball end of the latch member l2 therewith, is formed in two separate parts consisting of a backing plate 28 and the front plate 23. The backing plate 28 is fixedly secured within a recess in the door jamb by the screws 3%), whereas the separate front plate 23 is secured upon the backing plate 28 through the medium of one or more adjustable screws 3| by which the distance of the front plate 23 with respect to the backing plate 29 can be readily adjusted under the influence of the spacing springs 32'. It is possible, therefore, with, the strike. plate in situ, and without interfering with the door construction in. any way, simply by adjustment of the screw, or screws 31,. to so adjust the front. plate 23 that the same will bear a definite relationship with respect to the ball end of the latch member i2 and which corresponds to the required closed condition of the door. Such provision for adjustment finds considerable use and advantage in the case of the associated doorexpanding or contracting due to weather and other conditions which bring this about, as is well known, and which has hitherto given rise to considerable objection in connection with door constructions generally. 7

Whereas the handle 2| is fast upon the spindle 2B the other handle, which constitutes the outside door handle, may be free upon this spindle but is capable of being keyed thereto when desired. For this purpose the outside door handle 22 normally has a freely rotatable fit upon the spindle 2B and is located upon the latter by a threaded pin 33 engageable with anannular groove 34 on the spindle. This pin 33 however is capable of adjustment to cause it to. press tightly against the base of the groove and thereby cause the handle 22 to become. temporarily locked for rotation with the spindle if this is desired and which, if effected, will enable the cam It to be actuated by rotation of the handle 22 as well as by rotation of the handle 2i.

Having thus described our invention, what we claim and desire to protect by Letters Patent is:

1. A door latch structure comprising a tubular body part defining an opening at one end through which a latch member is projeotable to effect latching and unlatching, a latch member in the form of a primary plunger slidably mounted in one end of said tubular body part, said latch member including a latch nose portion projectable through said opening and a guide portion within the body part, an end closure at the opposite end of said body part and having a guide opening therein, a secondary plunger slidably mounted in said body part at said opposite end. said secondary plunger including a portion slidably guided in said guide opening, a first and relatively light coil spring in said body part and havingits ends permanently engaged with the said latch guide portion and said secondary plunger so as constantlyto urge both said latch nose portion. through; said first opening and said secondary'plunger against said end. closure. a second and relatively strong coil spring also mounted in said body part between said guide portion and said plunger, and a door handle and shaft, a cam on said shaft in engagement with said slidably guided plunger portion in said guide opening and adapted for adjustment positively to hold said secondary plunger in an inwardly displaced position within said body part, in which position said relatively strong coil spring is compressed to react against said latch member and render the same substantially rigid against unlatching.

2. The invention as defined in claim 1, said latch member guide portion comprising a screwthreaded spindle, and a collar screw engaged with said spindle and adjustable therealong, said collar having one end of said coil springs abutting thereagainst.

3. The invention as defined in claim 1, said body part having a screw-threaded end portion and said end closure having adjustable screwed engagement with said end portion.

DAVID JOSEPH SEAMAN. ALBERT EDWARD WOOD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

